1. Field of the Invention
The present invention relates to a deflector positioned between electron beam lens in a micro-column electron beam apparatus used for exposure process for patterning a photoresist film, and more specifically to a deflector having a plurality of deflecting plates correspondingly arranged at the upper and lower sides thereof and method for fabricating the same.
2. Description of the Prior Art
In general, a micro-column electron beam apparatus is used in an exposure process for patterning a photoresist film. In the micro-column electron beam apparatus, the photoresist film is exposed to a designed form by electron beam emitted from a cathode. The micro-column electron beam apparatus consists of electron beam lens through which the electron beam passes, and a deflector that electrically controls direction of the electron beam and positioned between the electron beam lenses. The micro-column electron beam apparatus receives data of a designed form from a pattern generator, and irradiates the electron beam to a photoresist film formed on a mask or wafer with a direction commanded by the data. Thereby, the photoresist film is exposed to the designed form.
The deflector has pairs of 2xcx9c16 deflecting plates arranged opposite to each other at the upper and lower sides of the deflector. The deflecting plates control the path of the electron beam in accordance with the data supplied from the pattern generator.
In fabrication process of the deflector, the deflecting plates are made by a wet etching or Deep RIE (reactive ion etch) process of a silicon wafer having a thickness of 0.2 mm to 1 mm, and anodic bonded on both sides of a base isolation plate consisted of Pyrex Glass, etc. However, as this conventional method has to make deflecting plates and fix them on both sides of the base isolation plate, alignment and uniformity between the deflecting plates cannot be easily improved, and reproducibility and structural durability cannot also be improved.
It is therefore an object of the present invention is to provide a deflector of a micro-column electron beam apparatus capable of eliminating above mentioned disadvantages by forming simultaneously plurality of deflecting plates at the upper and lower sides of the base isolation plate though metal plating process, and method for fabricating the same.
To achieve the above object, the deflector of a micro-column electron beam apparatus in accordance with the present invention comprises an isolation substrate having a hole formed at center of the isolation substrate; plurality of deflecting plates formed along circumference of the hole at upper and lower sides of the isolation substrate; plurality of pads formed on edges of the upper and lower sides of the isolation substrate; and plurality of wirings for connecting each of the deflecting plates and each of the pads, wherein the deflecting plates, wirings, and pads are formed integrated.
A hole through which electron beams pass is formed within the hole by arrangement of deflecting plates, and the deflecting plates are arranged opposite to each other with the isolation substrate.
The isolation substrate is made of ceramic alumina, and the deflecting plates, wirings, and pads are made of beryllium, phosphor bronze, bronze, cupro-nickel, stainless steel, or nickel, and formed by plating process.
In addition, a method for fabricating a deflector of a micro-column electron beam apparatus in accordance with the present invention comprises a step of burying and hardening polymer in a hole formed at center of a substrate; a step of forming first mask pattern so that some portion of seed metal layers is exposed to form deflecting plates, wirings and pads after forming the seed metal layers on both surfaces of the substrate; a step of forming first metal layers on the exposed portion of the seed metal layers; a step of forming second mask pattern on both surfaces of the substrate to expose the first metal layers in which the deflecting plates are to be formed; a step of forming second metal layers on the exposed portion of the first metal layers; a step of removing the first and second mask patterns; and a step of removing the seed metal layers exposed and polymers buried in the hole.
The first mask pattern is a photoresist film, and formed by coating or laminating process, and the first and second metal layers are made of beryllium, phosphor bronze, bronze, cupro-nickel, stainless steel, or nickel, and formed by plating process.
The second mask pattern consists of polymers, and formed by laminating process.
The step for removing polymers buried in the hole further comprises a step for plating metal on exposed surfaces of the first and second metal layers.
Although the present invention has been described in conjunction with the preferred embodiment, the present invention is not limited to the embodiments, and it will be apparent to those skilled in the art that the present invention can be modified in variation within the scope of the invention.